The present invention relates to diaphragm valves in general, and more particularly to improvements in diaphragm valves for withdrawal of liquid samples from pipes. The diaphragm valve of the present invention can be utilized with advantage for removal of samples from pipes which contain a liquid (particularly water) of predetermined microbiological purity.
The article "Mikrobiologische Prufung des Wassers im Rahmen der Inprozess-Kontrollen" by H. Bickel and K.-H. Meyer (published in "Die Pharmazeutische Industrie", Pharm. Ind. 42,1, pages 285-290, Editio Cantor, D-7960 Aulendorf, German Federal Republic) discloses a diaphragm valve which can be utilized for the above outlined purposes. When a nipple of the body of the valve which is disclosed in the aforementioned article is to receive a sample of the liquid medium, it must be subjected to flaming in order to ensure that the surfaces surrounding the path for the evacuation of samples are properly sterilized. This is a time-consuming operation and the application of heat is likely to result in damage to sealing elements including the diaphragm.